[67_Valiant]

Since there seemed to be some interest in this, I'm going to post progress(when possible) on a stock ecodiesel engine rebuild I am doing. This engine came out of a truck that I bought at an auction. It had an engine fire, at around 95k miles and was salvaged. All the damage was confined to the engine compartment, and the rest of the truck is in good condition.
The truck is a 2015 Ram BigHorn with a quad cab and shortbed. It has a few other nice features (tow package, heated seats and steering, 8.4" touchscreen, among other things).

Based on a previous bad experience, I decided it would best to pull the engine and go through it rather than just trying to get it running and drive it. It turns out the engine wasn't badly hurt, but definitely needed to be pulled as I will relate later on.

I have already pulled the engine out of the truck and it is completely torn down. It's worth noting that I was able to pull the engine without removing the cab, and was even able to leave the hood on, but just about everything else on the front end had to come off. Here are some pictures of the truck from the auction:

 

[67_Valiant]

Before purchasing a bunch of parts, I wanted to tear the engine down to understand what I was dealing with. I had already taken 2 of these apart previously, and both were beyond repair. I found that the crankshaft was in good condition (no spun bearings), but was showing wear on all the bottom shells. Additionally, 2 of the glow plugs were dead, one of which ended up breaking off just the tip inside the head. Finally, water had gotten into the #5 cylinder and was rusting the cylinder wall. I decided that it was fixable, and started researching part availability and ordering what I could find.

 

[Dennisvab]

Following this thread and looking forward to some updates! Good luck!

 

[67_Valiant]

Main Bearings:

Part Number: MB4556SX (King Bearing)

I am going to start with the mains because it's what I'm working on at the moment. Mopar does not sell these anymore (even though many sites are still listing them as available). They use a color-coding method for specifying bearings which is more common with newer vehicles, but was totally new to me. To make matters worse, there are no specific tolerances called out, but rather a tolerance stack is developed by using the specified combination of bearing colors (top and bottom can be different colors). The bearing codes are stamped to the front of the block, and the front crank counterweight.

All this said, there is a way to decrypt the Mopar specification table, and after backward-calculating their data, I ended up with a range of 0.0024"-0.0039" for the mains. I'm hoping to validate this through feedback from others as well as my own hands on experience with the engine I'm working on.

I ordered mains from Summit racing at a reasonable price ($103), and received them today. Here are the factory and King bearings side by side (factory is the darker one):

I went ahead and took some shell thickness measurements and found the King bearing to be ever so slightly thinner (King bearing averages 0.0796" vs factory 0.0799").

Next, I put the new bearings in the engine with plastigage. I'd like to describe the procedure i used to see if anyone has any objections to it:

I'm used to engines with individual main caps, and always measure the mains one at a time. However, in the case of the ecodiesel, the bedplate has 29 bolts holding it together with a LOT of pressure. I decided to just put the plastigage on each of the mains and measure them all at once. The other "deviation" from what might otherwise be recommended is that I used the old main bolts (which are torque-to-yield), and tightened everything down per the spec. One could argue that this may result in a false reading, but what I found leads me to believe it is OK. I will be using new bolts for final assembly. After taking everything back apart, here are the measurements front to rear:

#1 Main: 0.0020"
#2 Main: 0.0015-0.0020" (was in between marks on the plastigage scale)
#3 Main: 0.0020"
#4 Main: 0.0020"

This is at the tighter end of the range I had calculated, however I am rationalizing that the RTV in-between the bedplate and block has to be at least 0.0005" thick.

That's it for now. I'll add more as time permits

 

[Bat Koce]

If you are accointing for the RTV thickness and did the plastigauge test without RTV, don't you think you overcompressed the bearings and when you do the final install the bearings might get loose between the bedplate and the block.

Sent from my SM-N960U using Tapatalk

 

[67_Valiant]

If you are accointing for the RTV thickness and did the plastigauge test without RTV, don't you think you overcompressed the bearings and when you do the final install the bearings might get loose between the bedplate and the block.

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I don't think it would be enough compression to cause plastic deformation in the bearings, but definately worth checking. I will inspect them under magnification and check if there's any distortion around the points of contact.

 

[Dennisvab]

That’s interesting that you just apply sealant between block and bedplate. It seems like depending on how much sealant you apply, your tolerances may vary. Maybe it’s a moot point, and what needs to be squeezed out will come out. On the Bmw N55 gasoline engine, they also use a bedplate. However there is a groove in the plate and block. After bedplate is installed, you apply sealant to this groove through a port on the side of the block.

 

[Bat Koce]

I don't think it would be enough compression to cause plastic deformation in the bearings, but definately worth checking. I will inspect them under magnification and check if there's any distortion around the points of contact.

If I remember right someone on the forum said that these are crush bearings.

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[67_Valiant]

I believe they are crush bearings.

I looked at them after installation, and I don't see any evidence of cupping at the ends (where they would be in contact). On the backside, there is an even pattern of contact with the journal, so I think it will be OK.

In hindsight, to be totally accurate, I should have added the RTV (I will next time!). As a point of reference, all my mains were factory spec's as "blue" (BBBB-Crank, BBBB-Block). Since there are no measurement instructions in AllDataDIY, I'm going to call a machine shop today to see if they would have done it any differently.

 

[67_Valiant]

I've been doing more research on the "colored bearing" approach to engine manufacturing. Based on what I've read, I've come to the conclusion that the different sized bearings are used to compensate for manufacturing variations by custom fitting each bearing half to each main on the block side rather than the crank side (this may be obvious to some, but I'm putting it out here for refutation by anyone who knows different).

If this is correct, then engines which originally had different upper and lower bearing colors would most likely need to be line-bored before using the King bearings. In the case of my engine, they were all "Blue", and all the mains were within a range of 0.0015"-0.0020", so I am going to proceed without line-boring.

I did call a local machine shop that works on Sprinter engines (Mercedes v-6 3.0 diesel) as well as a few ecodiesels, and they felt I was good to go with the clearances I measured.

Next will be either rod bearings or pistons (depending on which parts/tools arrive first)

 

[Bat Koce]

Thank you for this info!
What brand bearins did you order for the rods?
Are you changing the pistons as well??

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[MAS]

I did call a local machine shop that works on Sprinter engines (Mercedes v-6 3.0 diesel) as well as a few ecodiesels, and they felt I was good to go with the clearances I measured.

I thought the 3.0 diesel in the sprinters was a 3.0 liter in-line 4 cylinder?

 

[67_Valiant]

Thank you for this info!
What brand bearins did you order for the rods?
Are you changing the pistons as well??

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They are also from King Bearing. I'm expecting them today, so i'll post more info once they arrive. I'm keeping the old pistons, but I did quite a bit of cleanup on them. The rings were pretty caked with soot, and sticky in the ring land.

 

[67_Valiant]

I thought the 3.0 diesel in the sprinters was a 3.0 liter in-line 4 cylinder?

I think they also have an in-line 4, but the one I'm referring to is this
It actually has the same bore as the VM L630, but uses slightly different rings (Chrome top vs. Moly for L630)

 

[RansomT]

The motorcycle world has been using color coded bearings for several years. The cases are "supposed" to be used in machine sets, so that you don't mix the bearing colors. You measure the crank journal and match the bearing size to it. Then you check with plastigage and make changes as needed. The sizes of the different bearings and tollerances are so "small" that you really need multiple sets of bearings on hand to do the job right. If VM is mixing the bearing shell sizes at the factory, then that is an issue. Might be away for them to pushing through the manufacturing proccess of an engine that otherwise would be trashed/recycled.

 

[67_Valiant]

The motorcycle world has been using color coded bearings for several years. The cases are "supposed" to be used in machine sets, so that you don't mix the bearing colors. You measure the crank journal and match the bearing size to it. Then you check with plastigage and make changes as needed. The sizes of the different bearings and tollerances are so "small" that you really need multiple sets of bearings on hand to do the job right. If VM is mixing the bearing shell sizes at the factory, then that is an issue. Might be away for them to pushing through the manufacturing proccess of an engine that otherwise would be trashed/recycled.

Most of the info I found was from the motorcycle sites

It's clear to me that they do mix colors on the same journal (at least for the mains). Take a look at the 2nd image below which is the crank from the 2nd motor I took apart. You can see it is stamped "BABA". I can't find a picture of the old block, but as I recall, it was stamped BBBB. The 3rd picture shows that they do have a spec for mixed Red and Blue (I'm guessing that is part of the reason they were sold individually). Also note, that the rod bearings were sold in pairs only.

Bottom line, I'm convinced that they built some engines with mixed colors on the same journal.

 

[67_Valiant]

Before I jump into the rod bearings, here are some couple interesting writeups on bearing failure and bearing clearances:

1) https://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/catalogs-and-literature/engine-bearings/ceb-2-1114-engine-bearing-failures-brochure.pdf
2) https://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/cl77-1-205r.pdf

Of particular interest, the latter article has the following comment regarding modern engines: "Most passenger car engines are originally assembled by “selectfitting” to achieve clearances that are less than what would resultfrom random selection of mating parts.".

 

[67_Valiant]

Rod Bearings

Part Number: CR6900SV

I received the rod bearings from Summit this past week. They look identical to the factory units.

When installed, the clearances came out as follows:

Cylinder Rod	Clearance
#1	0.0015"
#2	0.0020"
#3	0.0020"-0.0025"
#4	0.0020"
#5	0.0020"
#6	0.0020"

Here are the factory specifications for the rods:

Following the rule of thumb of 0.001" clearance per inch of journal diameter, I should be targeting ~0.0027" +/-, so most of my tolerances are on the tight side. Hopefully, the 5W/40 will still work OK.

 

[67_Valiant]

Taking a quick break from the mechanical stuff for a moment, I wanted to share a cool hack that I came across recently that saved my several hundred bucks on a wire harness.

Whoever owned my truck previously must have panicked during the fire, and cut all the positive battery cables at the battery terminal (there are 7 total cables on this one junction!):

By using some of the techniques in this video:

I was able to save the wire harness. The only thing I did differently was to put flux on the wires prior to crimping and wick solder into the joint. It turned out like this:

 

[MR. TED]

Nice to learn little tricks like this.... Nice work.. Thank You !